Examples of biodegradable molded objects include containers or cushioning materials such as trays, cups, and corner pads, and molded baked snacks such as ice-cream cones, monaka, and wafers. One method for manufacturing this kind of biodegradable molded objects is the external heating method, wherein materials for the molded objects are placed into a mold previously heated to a predetermined temperature, and molding is performed using heat conductivity.
However, such a method has drawbacks in that a long molding time is required thereby leading to low productivity, and that unevenness in the temperature of the metal mold causes uneven baking, thus making it impossible to obtain a uniform consistency.
For this reason, in another method, alternating current is supplied to a metal mold so that heat is generated in the materials by dielectric heating, and with this heat, the materials are baked and molded. In this case, the metal mold is divided into two mold halves, which are insulated from each other by an insulating material provided therebetween, and alternating current is connected to each mold half, so that the materials in the mold are baked and molded by dielectric heating.
The foregoing manufacturing method by dielectric heating is, however, unsuited for mass production and is difficult to realize, since it is a method wherein power is supplied by direct contact, and moreover, the foregoing method has a drawback in that adjustment of output is complicated.